Many available firearms utilize a cartridge magazine for holding a number of cartridges to be received into the firearms. Prior magazine cartridges are configured such that each magazine can only be used with one type or style of firearm. As a result, a user of more than one firearm must keep on hand a number of different cartridge magazines. In addition to increasing the inventory of magazines, this lack of interchangeability results in an increased cost to the user because the user must buy more than one type of magazine for use with each different firearm. Also, the non-interchangeability factor can be a serious concern in the law enforcement area. Law enforcement officials commonly carry more than one firearm. When time is critical, such as occurs occasionally during the performance of the duties of a law enforcement official, there is a serious time disadvantage in having to be concerned about selecting the proper magazine for the chosen firearm.
This interchangeability problem relating to cartridge magazines is found in firearms known as the M16/AR-15, the AR-180, a firearm similar to the M16/AR-15, and the Ruger Mini-14/AC 556, as well as other styles of firearms. M16/AR-15 is a gun model designation of Colt Industries Operating Corp., located in Connecticut, Ruger Mini-14/AC 556 is a gun model designation of Sturm, Ruger & Company, Inc., located in Connecticut and AR-180 is a gun model designation of Armalite, Inc., located in California. Such conventional styles of cartridge magazines are non-interchangeable in the sense that a conventional cartridge magazine which is functional in the M16/AR-15 style of firearm cannot be used in the Ruger Mini-14/AC 556 style of firearm. Similarly, the conventional magazine used in the Ruger Mini 14/AC 556 style of firearm cannot be used in the M16/AR-15 style of firearm. It should be noted that this lack of interchangeability is not limited to just these two magazines but is prevalent among a great number of magazines. The non-interchangeability drawback associated with cartridge magazines exists because of a number of structural differences that are found on the various styles of firearms.
Cartridge magazines adapted for use with firearms typically include latching elements or parts that are used to engage latching mechanisms found on firearms. By way of example and with regard to each of the cartridge magazine latching mechanisms of the above-identified two styles of firearms, each such mechanism is different from the other style of firearm. In particular, the cartridge magazine latching mechanism used on the M16/AR-15 style of firearm is of such a nature that its cartridge magazine must have a slot on one of the walls of the magazine. The Ruger Mini-14/AC 556 style of firearm has a cartridge latching mechanism of such a nature that its cartridge magazine must have a ledge on a first narrow wall of the cartridge magazine and a slot on the second narrow wall of the magazine.
The straight-forward combination of the various latching parts into a single cartridge magazine cannot be achieved to produce a magazine which is adaptable for use with all three styles of firearms, for a number of reasons. First, a vertically extending projection found on one of the the M16/AR-15 magazine walls would not permit proper operation of the latching mechanism found on the Ruger Mini-14/AC 556 firearm. Secondly, the conventional Ruger Mini-14/AC 556 cartridge magazine has a width greater than the maximum width of a magazine which can be used with the M16/AR-15 firearm. Conversely, the conventional M16/AR-15 cartridge magazine has a thickness greater than the thickness of the conventional cartridge magazine which can be used with the Ruger Mini-14/AC 556 firearm. In addition, the M16/AR-15 conventional style of firearm includes a protrusion next to its latch-engaging slot. This protrusion prevents proper engagement by the Ruger Mini 14/AC 556 firearm with the conventional M16/AR-15 magazine. Also, the length of the member on the conventional magazine follower used to hold the bolt open on the M16/A-15 firearm is so great such that, if this magazine could be used with the magazine of a Ruger Mini 14/AC 556 style of firearm, this bolt hold open member would undesirably hit that surface in the firearm located below the bolt when the magazine is rotated to disengage the latching lever of the firearm from the magazine, after the last cartridge has been loaded.
Despite the foregoing incompatibilities among the cartridge magazines such styles of firearms, several advantages result from the development of an interchangeable cartridge magazine for use with different styles of firearms. In that regard, the present invention is directed to providing a cartridge magazine adapted for use with a plurality of styles of firearms, and particularly adapted for use with both the M16/AR-15 and Ruger Mini-14/AC 556 styles of firearms.